diff --git a/src/sprites/clone.js b/src/sprites/clone.js
index 9c7537d27..ba025ab73 100644
--- a/src/sprites/clone.js
+++ b/src/sprites/clone.js
@@ -205,7 +205,7 @@ Clone.prototype.setCostume = function (index) {
     this.currentCostume = index;
     if (this.renderer) {
         this.renderer.updateDrawableProperties(this.drawableID, {
-            skin: this.sprite.costumes[this.currentCostume].baseLayerMD5
+            skin: this.sprite.costumes[this.currentCostume].skin
         });
     }
 };
@@ -221,7 +221,7 @@ Clone.prototype.updateAllDrawableProperties = function () {
             direction: this.direction,
             scale: [this.size, this.size],
             visible: this.visible,
-            skin: this.sprite.costumes[this.currentCostume].baseLayerMD5
+            skin: this.sprite.costumes[this.currentCostume].skin
         });
     }
 };
diff --git a/src/sprites/sprite.js b/src/sprites/sprite.js
index 9add2c719..0d2b6b70e 100644
--- a/src/sprites/sprite.js
+++ b/src/sprites/sprite.js
@@ -7,14 +7,34 @@ var Blocks = require('../engine/blocks');
  * @param {?Blocks} blocks Shared blocks object for all clones of sprite.
  * @constructor
  */
-function Sprite (blocks, name) {
+function Sprite (blocks) {
     if (!blocks) {
         // Shared set of blocks for all clones.
         blocks = new Blocks();
     }
     this.blocks = blocks;
-    this.name = name;
+    /**
+     * Human-readable name for this sprite (and all clones).
+     * @type {string}
+     */
+    this.name = '';
+    /**
+     * List of costumes for this sprite.
+     * Each entry is an object, e.g.,
+     * {
+     *      skin: "costume.svg",
+     *      name: "Costume Name",
+     *      bitmapResolution: 2,
+     *      rotationCenterX: 0,
+     *      rotationCenterY: 0
+     * }
+     * @type {Array.<!Object>}
+     */
     this.costumes = [];
+    /**
+     * List of clones for this sprite, including the original.
+     * @type {Array.<!Clone>}
+     */
     this.clones = [];
 }